Lock stitch sewing machine



'P 1945- H. .1. LE VESCONTE ET AL 2,385,288

LOCK STITCH SEWING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet l FIG l murals.- Harold lid 25cm Ze,

BY 4 fllberi 17' 5611112612311.

A TTORN E YS Sept. 18, 1945. 'H. J. LE VESCONTE ETAL 2,335,283

LOCK STITCH SEWING MACHINE 5 Sheets-Sheet 2 Filed Dec. 12, 1940 Q j n I N a M Q [Q a I 1 a INVENTORS:

Ag BY ATTORNEYS.

Sept. 18, 1945. H. J. VESCONTE ET AL 2,385,288

LOCK STITCH SEWING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet 3 IN VEN ToRs fiamld J Le%'sc01zi 4' fllberl m 5m wada'.

ATTORNEYS.

Sept. 18, 1945. H. J. LE VESCONTE ET AL 2,385,288

LOCK STITCH SEWING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet 4 I N VEN TORS I WITNESSES; I 04% Z iiarolal lelscmtg M BY 43 fllflfli'i IZSc/weda.

M ATTORNEYS.

Sept- 1945- H. J. LE VESCONTE ET AL 2,385,288

LOCK STITCH SEWING MACHINE Filed Dec. 12, 1940 s SheetsSheet 5 FIGzJLZ l jla,

62 am. 5m 6m l N VEN TORS WITNESSES; Ojfi 2) Harold 1136145000122, M BY 4 film/"i [*[Sc/zzmdn.

ATTORNEYS.

Patented Sept. 18, 1945 2,385,288 7 LOCK s'rrrcn srwmo meme Harold J. Le Vesconte, Western Springs, and Albert M. Schweda, Chicago, Union Special Machine Company, a corporation of Illinois assignors to Chicago, 111.,

Application December 12, 1940, Serial No. 369,766

21 Claims.

This invention relates to lock stitch sewing machines, and is more especially concerned with lock stitch sewing machines of the type in which the rotary hooks revolve about vertical axes.

The present invention constitutes an improvemounting, there is an oil well which communicates with the open lower end of the hollow hook shaft, and the top of the axial hollow in said shaft communicates, in turn, by way of a lateral duct with the raceway of the hook. A pump means depending for its action upon the rotation of the hook, elevates the oil through the hollow of the shaft for conveyance by the lateral duct to the raceway, and while a porous plug in the top of the shaft hollow is relied. upon to govern the rate of oil flow to said raceway.

An object of our invention is to provide, a sewing machine organization of the character referred to, for more definitely controlling the rate of oil flow into the hook raceway and thus prevent the release of excess oil which might soil either the sewing threads or the work being operated upon. This desideratum we attain, asv

more fully disclosed hereinafter, through incorporation in this hook unit of a simple and inexpensive valve means which can be accurately adjusted to regulate the oil flow in accordance with the speed of the machine.

Another aim of our invention is to obviate the necessity for frequently replenishing the oil in the well of the hook mounting whereof the capacity is necessarily small. This advantage is attained as also hereinafter more fully brought out, through provision of a main supply reservoir of relatively large capacity, and'of means by which the oil is conducted from the reservoir to the hook mounting and which will allow the shifting of said mounting when the hooks are positionally adjusted relative to the cooperating needles.

Another object of our invention is to attain the above advantages with means for conveying lubricant to the raceway of the rotary hook which is accessible for cleaning without necessitating removal of the hook from the sewing machine.

Uur invention is also directed toward making it pcsstble to supply oil to the raceways of a plurality of rotary hooks from a common source of supply.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein Fig. 1 is a fragmentary view in top plan of a sewing machine conveniently embodying our invention.

Fig. 2 shows the machine in bottom plan.

Fig. 3 is a detail view in longitudinal section taken as indicated by the angled arrows III-III inFig. 2.

Fig. 4 is a cross section of the machine taken as indicated by the angled arrows IV-IV in Figs. 1 and 2.

Fig. 5 is an exploded view showing the component parts of one of the rotary hooks of the machine.

Fig. 6 shows the top plan of the rotating component of the hook with a portion thereof broken out and in section, the sectioned portion being taken along the line indicated by the angled arrows VI-VI in Fig. 4.

Fig. 7 is a perspective view of an oil lifting element whereof one is associated with each rotary hook.

Figs. 8 and 9 are perspective views respectively of a gasket and closure plate associated with each rotary hook mounting.

Fig. 10 is a fragmentary detail section taken as indicated by the angled arrows XX in Fig. 1.

Fig. 11 is a view, largely in plan, of the rotating component of a rotary hook corresponding to Fig. 6, but with the sectioned portion taken at a lower level as indicated by the angled arrows XI-XI in Fig. 4.

Figs. 12 and 13 are views respectively showing the rotating component of the hook in side elevation and in bottom plan.

Figs. 14 and 15 are views like Figs. 4 and 6, showing an alternative embodiment of our invention; and

Figs. 16 and 1'7 are respectively a perspective view and a longitudinal sectional view of 081'? tain parts of the alternative embodiment- The illustrated sewing machine is of the flat bed type having an oblong work support i, whereof the leit hand end is formed with a longitudinally-extending slot 2 which is centrally bridged by a transverse throat plate 3. As shown, the throat plate 3 has a pair of contiguously-arranged elongated openings 4 and 5 for upward protrusion of the toothed sections 6 and i of a four motion feed dog. In Fig. 2, the lower end of the shank of the feed dog is shown at B and the carrier bar therefor at 9, the latter being connected to a rocker It on an oscillating shaft II which is Journaled in fixed bearing lugs l2 and I3 below the work support By suitable means not illust ated, a pair of needles l5 and I6 i vertlcally-reciprocated to pass up and down through apertures l1 and i8 in the feed dog sections 6 and 1, and which in the present instance, are also vibrated laterally to assist the feed dog in intermittently advancing fabric crosswise of the work support Arranged to cooperate with the respective needles l5 and I6 in stitch formation below the work support are rotary hooks and 2| which are identical in construction, and respectively carried by bracket-like mountings 22 and 23'. As shown in Fig. 2, the mountings 22, 23 are slotted as at 25 and 26 for penetration by the shanks of clamp screws 21, 28 which respectively engage into aligned g-uide ribs 29, 30 at the underside of the work support. The mountings 22, 23 are moreover provided with split clamp arms 3|, 32 which embrace bearing sleeves 33, 34 wherein a longitudinally extending shaft 35 is iournaled, said sleeves being fixed in spaced bearing lugs 36, 31 pendant from the work support and said collars being provided with clamp screws 38, 39. This arrangement, permits accurate adjustment of the rotary hooks 20 and 2| relative to the needles l5 and I6. At its right hand end, the shaft 35 extends into a pendant housing 48 on the work support containing the drive mechanism (not shown) of the machine. The rotary hooks 26 and 2| are actuated through inter-meshing spiral gear pinions 4|, 42 and 43, 44, whereof the pinions 4|, 43 are secured to the shaft 35 with capacity for being positionally shifted therealong to suit the adjustments of the rotary hook mountings. As already stated, the rotary hooks 20 and 2| are identical in construction, as are .also the hook mountings 22, 23, except that the latter are made as rights and lefts. Accordingly the following description of the hook 26 and its mounting 22 will be understood to hold also for the second hook and its mounting. As shown in Figs. 1, 4, 5, 6 and 11, the rotary hook 28 comprises a cup-like rotating component 45 with a needle loop seizing beak, and a nonrotating component 41 which occupies the hollow of the first, which in turn contains the usual secondary thread supply spool or bobbin 48. As shown, the rotating component 45 is provided with an internal annular raceway 49 formed in part by a removable gib 50, said raceway being engaged by a circumferential rib 5| on the nonrotating component 41. The rotating hook component 45 moreover has a pendant tubular shaft 52 journaled in bushings 53 and 54 fixed in upper and lower lateral bearing projections 55 and 56 (Fig. 4) on the mounting 22 and suitably spaced for accommodation between them of the gear pinion 42. The hook shaft 52 terminates short of the bottom of the bore in the lower bearing 56 for communication, by way of a passage 51, with an adjacent vertical cavity 56 in the mounting which serves as an oil well, said bore being closed at the bottom, with interposition of a sealing gasket 59 (Fig. 8), by a removable screwsecured cover plate 60 (Fig. 9). Projecting upward into the hollow of the hook shaft 52 with a relatively loose fit is a core pin 6| (Fig. 7). As shown, this core pin 6| is formed with a lengthwise extending spiral groove 62, and also with a squared bottom end 63 for engaging a similarly configured recess 64 in the cover plate 60 to prevent its rotation with the hook shaft 52.

By coaction between the groove 62 of the stationary core pin 6| and the inner rotating surface of the hook shaft 52, oil is lifted from the well 58 to the upper end of the shaft hollow which is closed by a removable disc 65 forcefitted into an axial recess 66 in the bottom of the cup-like rotating component 45 of the hook. Leading first laterally from the upper end of the hook shaft hollow and then upwardly to the annular raceway 49 in the'rotating component 45 is a duct 61; and lodged in the hook shaft hollow above the top of the core pin 6| is a porous plug 68 through which the oil is obliged to percolate slowly. While the plug 68 acts to govern the flow of the oil into the duct 61 leading to the raceway 49, we have provided additional means whereby the amount of oil released into said raceway may be accurately regulated to insure against flooding and preclude soiling of either the sewing threads or the material being worked in the machine. As shown in Figs. 11-13, this oil flow regulating means includes a screw 69 which is threaded into the rotating component 45 of the hook from within a cut-out 1|) at the bottom of said component, and which has its diametrically reduced plain cylindric inner end 1| extending crosswise of the laterally extending portion of the oil flow duct 61. By rotation of the screw 69 in one direction or the other it will be seen that the amount of oil released can be regulated to a nicety in accordance with the speed of the machine, to provide the exact amount of lubrication desired. A spring locking element 12 adjustably secured by a screw 13 within the cut-out 10 with its free end bent at right angles and apertured for penetration by the shank of another screw 69, operates to exert outward pressure upon the head of the latter screw to hold it against the possibility of accidental turning incident to the high speed rotation of the hook.

Due to the smallness of the hook shaft journal portions of the hook mountings 22, 23, the capacity of the oil wells 58 is correspondingly limited. Accordingly in order to preclude the necessity for frequent replenishment of the oil in the wells 58 we have provided, below the work support l, a common source of oil supply of large capacity in the form of a reservoir 15 which is of L shaped configuration in plan (Fig. l) and whereof the side walls are preferably made integral with said work support. As shown in Figs. 3 and 10, the bottom of the reservoir 15 is closed by a removable plate 16 which is sealed by an interposed gasket 11 and secured by screws 18. From the reservoir 15, the oil is conducted to the Wells 58 in the hook mountings 22, 23 through tubes and 8| respectively. As shown in Figs. 2 and 3, the tubes 86 and 8| are fixedly engaged at one end in nipples 82, 83 screwed into'the hook mountlugs 22, 23, while their other ends fit telescopically into stufiing box fittings 84, 35 screwed into one of the side walls of the reservoir 15. The lateral adjustments of the hooks 20, 2| relative to the needles l5, l6 can thus be made without entailing disruption of the tube connections between the mountings 22, 23 and the reservoir 15. The oil supply in the reservoir 15 is normally maintained at the level indicated in Fig. 3 and this coincides with the level in the well 58 (Fig. 4) which, it will be noted is below the top of the lower hook shaft bushing 54 to prevent escape of oil at that point. The oil supply in the reservoir 15 is replenished when necessary, through an opening 86 leading downwardly from a small recess 81 in the top of the work support and having a filtercore pin 61a,

ing cap 88 secured over its bottom end by screws 89. Fitting into the iilling opening 86 is a removable measuring rod 90 with a grasp knob 9| at the top end normally within the recess 81, and having its bottom end flattened as at 92 for the purpose of a gauge and dipping into the oil.

In order to guard against restriction of tree oil flow from the wells 23 each of the latter is provided with an air vent duct 93 (Fig. 4) which leads first upwardly from the top of the well and then downwardly to a point 94 above the normal oil level in the reservoir so that the entry of lint or dirt cannot take place.

The modified form of our invention shown in Figs. 14-17 is identical with the first described embodiment except for shortening of the oil liftin and for the location, of the axis hollow of the rotating component of the rotary hook, of the oil flow regulating means of .which the construction is like that shown in U. S. Patent No. 2,112,172 granted to Richard Mackay, J r., on March 22, 1938. Briefly described this regulating means is in the form of a screw plug valve 69a with a conical head 95 intermediate the ends of a cylindric axial portion 96. In the assembly, the conical head 95 of the valve occupies a correspondingly tapered seat portion 91 of the hook shaft hollow; while the lower end of the cylindric portion 96 is provided externally with screw threads to engage internal screw threads medially of the height of the hook shaft. The top end of the cylindric pOrtionBB of the valve is provided with a screw driver slot 98 and projects upward with a fluid tight fit into a downwardly-flanged axial opening in a disc 99 which closes the top of the hook shaft bore. Access to the screw plug in this instance is thus possible simply upon removal of the non-rotating hook component 41a from within the rotating component 45a. The oil elevated by the action of the spiral groove of the core pin Bla reaches the conical seat 91 of the valve by way of a longitudinal groove Hill in the valve. At the bottom of the valve, the groove Hill is extended as a diametral slot which divides the threaded lower end of the valve, thereby rendering the latter springy for capacity to resist turning and disturbance of its adjustment as the hook rotates. In order to obviate repetitive description, all other elements shown in Figs. 14 and 15 and having their counterparts in the first described embodiment are identified with the same reference numerals previously employed with addition in each instance of the letter 01" for convenience of ready distinction.

Having thus described our invention, we claim:

1. In a lock stitch sewing machine, a vertically reciprocating needle; a cooperative vertical axis rotary hook comprising a rotating component with a pendant tubular shaft, and a non-rotating component having an annular groove and rib-bearing engagement with the rotating component; a journal mounting for the rotary hook having therein an oil chamber with which the axial hollow of the shaft communicates at its lower end; a duct leading laterally from the top of the shaft hollow to the groove and rib bearing; pump means operated through rotation of the hook to elevate oil within the shaft from the chamber for conduction to the groove and rib bearing; and adjustable means for controlling the rate of flow of the oil to the bearing.

2. A look stitch sewing machine according to claim 1, wherein the flow controlling means is 58 in the hook mountings 22..

within the top lodged in the lateral duct adjacent the point where it discharges into the bearing.

8. A look stitch sewing machine according to claim 1, wherein the flow controlling means is in the form of a valve screw which extends laterally into the duct adjacent the point where said duct discharges into the bearing.

4. A lock stitch sewing machine according to claim 1, wherein the non-rotating component of the rotary hook is within'the rotating component, and wherein the flow controlling means is in the form or a tapered screw plug within the upper end of the shaft hollow which screw plug is accessible for adjustment simply upon removal of the non-rotating hook component from within the rotating component.

5. A lock stitch sewing machine according to claim 1, wherein the pump means includes a nonrotating spirally-grooved core pin which extends upwardly into the hollow of the hook shaft and has more than a bearing clearance therewith.

6. A lock stitch sewing machine according to claim 1, wherein the hook mounting is supported with capacity for lateral adjustment relative to the needle; and further including a reservoir constituting a supply source for the oil, and a connection for conducting oil from the reservoir to the hook mounting which allows adjustment of the mounting for the aforesaid purpose.

'7. A lock stitch sewing machine according to claim 1, wherein the needle passes down through a work support; wherein the hook mounting is supported below the work support with capacity for lateral adjustment wherein a reservoir pendant from the work support constitutes a main supply source for the oil; and wherein there is a connection for conductin oil from the reservoir to the hook mounting which allows adjustment of the mounting for theafore- 40 said purpose.

8. A look stitch sewing machine according to claim 1, wherein the needle passes down through a work support; wherein the hook mounting is supported below the work support with capacity for lateral adjustment relative to the .needle; wherein a reservoir pendant from the work support constitutes a main supply source for the oil; wherein there is a connection for conducting oil from the reservoir to the oil chamber in the hook mounting which allows adjustment of the mounting for the aforesaid purpose; and wherein there is a filling opening leading downwardly through the work support into said reservoir.

9. In a lock stitch sewing machine, a plurality of needles, a plurality of relatively adjustable rotary hooks to cooperate with the individual needles in stitch formation; common driving means for said needles and hooks a main source of lubricant supply; and connections including pumping means connected directly with each hook and rendered operative by rotation of the hooks for conducting lubricant from the common supply source to all of the individual hooks.

10. In a lock stitch sewing machine, a plurality of vertically-reciprocating needles; vertical axis rotary hooks to cooperate with the individual needles in stitch formation; individual mountings in which the shafts of the hooks are journaled and having oil chambers within them; pump means within the mountings for elevating oil from the chambers to the raceways of the hooks; a main source of oil supply; and means for conducting oil from the main supply source to the hook mountings.

ii. In a lock stitch sewing machine, a plurality relative to the needle;.

] allowing individual adjustment of the mountings as aforesaid, for conducting oil from the main supply source to the mountings.

12. A lock stitch sewing machine according to claim 10, wherein the shafts of the hooks are tubular to receive oil at their bottoms from the oil chambers; and wherein the pump means includes non-rotating, spirally-grooved, loosely fitting core pins respectively within the shaft hollows.

13. A lock stitch sewing machine according to claim 11, wherein the shafts of the hooks are tubular to receive oil at their bottom from the oil chambers, and respectively have lateral oil conducting ducts extending to the hook raceways; and wherein the pump means includes nonrotating, spirally-grooved, loosely fitting core pins respectively within the shaft hollows.

14. A look stitch sewing machine according to claim 10, wherein the oil conducting means comprises tubes which extend from the individual hook mountings and which telescopically engage outlet fittings on a reservoir constituting the main source of oil supply.

' 15. In a lock stitch sewing machine, a vertically-reciprocating needle; cooperative complemental stitch forming means including a vertical axis rotating component, and a, non-rotating component with a bearing surface in engagement with the rotating component; variable action pump means connected directly with and operated in response to rotation of the rotating component aforesaid to elevate oil from a point below the bearing surface; means for delivering said oil to said. surface; and adjustable means operable independently of the speed of operation of the machine for controlling the rate at which the oil is pumped and at which it is delivered to said bearing surface.

16. The invention according to claim 15, in

which the adjustable oil pumping and delivery controlling means is carried by the rotating component of the complemental stitch forming means, is accessible without removal of the rotating component and is in the path of the oil between said pump and said bearing surface.

17. In a lock stitch sewing machine, a work support, a vertically-reciprocating needle; a cooperative complemental stitch forming means including a vertical axis rotating component, and a non-rotating component having a bearing surface in engagement with the rotating component; a source of oil supply below the level of the bearing surface; pump means connected directly with and operated in response to rotation of the rotating component to elevate oil from the supply to the bearing surface; and adjustable means accessible assaase through the top of the work support without removal of the rotating component at a point between the supply source and the region of application of the oil at the bearing surface for controlling the rate of pumping and of flow of oil to said bearing surface independently of the speed of operation of the machin 18; A vertical axis rotary .stitch forming element for a sewing machine, said element comprising a rigid unitary structure having a bearing surface to contact with an associated non-rotating element and including pump means operative by its rotation to assist in elevating lubricating oil to said bearing surface from a supply at a lower level, said element having means incorporated therein and accessible for adjustment without removal of any part of aid element for controlling the rate at which the oil is pumped and at which it is delivered to said bearing surface.

19. A vertical axis rotary hook element for a sewing machine, sai element comprising a rigid unitary structure having a bearing surface to contact with the bearing on an associated nonrotating element, a pendent hollow shaft including pump means operative through its rotation to assist in elevating oil to the raceway from a supply at a lower level, and adjustable means within the shaft hollow accessible without removal of any part of said element for controlling the rate at which oil is pumped and at which it is delivered to said bearing surface.

20. In a lock stitch sewing machine, a plurality of needles, vertical axis rotary hook units to cooperate with the individual needles in stitch formation, each of said hook units having a raceway, said hook units being adjustable toward and from each other, a stationary lubricant reservoir adapted to retain a lubricant for the hook units only, and connections from said reservoir to the raceways of all of said rotary hook units for conducting lubricant thereto, said connections being arranged to deliver the lubricant to said raceways from below the latter.

21. In a sewing machine a work support, a reciprocable needle, a vertical axis rotary hook cooperating with said needle in the formation of stitches, a stationary thread carrier journaled in a raceway in said rotary hook, a bracket member beneath said work support, a vertically disposed shaft connected with said rotary hook mounted in spaced upper and lower hearings in said bracket, driving means for said shaft including a gear fixed to said shaft between said bearings, lubricating means for said raceway including a reservoir disposed beneath the upper level of the lower bearing, means for delivering oil from said reservoir to said raceway in part through said shaft, said oil delivering means serving to place said lower bearing in constant communication with said reservoir for delivery of oil by gravity to said bearing, and adjustable means interposed between said reservoir and said raceway and accessible without the removal of said rotary hook for varying the flow of lubricant to said raceway.

HAROLD J. LE VESCONTE. ALBERT M. SCHWEDA. 

